[ashmostro]

I don't have an evidence to discount your theory, but if it is a software issue, why would my sensor have gone from functioning fine to acting in the same intermittent way as the OP described?

[Efthreeoh]

Originally Posted by ashmostro

I don't have an evidence to discount your theory, but if it is a software issue, why would my sensor have gone from functioning fine to acting in the same intermittent way as the OP described?

Well, when the car reaches 300,000 kilometers BMW has programmed the CBS to stop using the oil quality data the sensor produces for the algorithm that calculates the oil change interval, so the oil monitor system goes defunct at the next oil change past 186,000 miles; and the car constantly reminds you that the oil service is past due. So this means that software is highly involved in the processing of the data that comes out of the sensor, be it oil level data or oil quality data. I've never seen perfect software.

Once my car reached this point the oil level reporting has entirely changed from the way it operated prior to that mileage. And I changed the sensor to fix it, which didn't affect the new behavior of the system, so I took the car to BMW and that is when I found out about the programming. BMW supposedly has a software fix for it, but it doesn't work (discovered only after they had my car for a week).

[ashmostro]

Right, but that's not the "undocumented feature" that applies here.

Capacitors can fail. Terminations can fail. Am I sure that's what is happening here? No... But it feels more like an electro-mechanical issue to me by its correlation to temperature.

Actually I suspect moisture in the oil is to blame (affects the dielectric constant), which is why reports of this issue are so common in the winter and almost non events in warmer climates. But that's just one of my theories. Replacing the sensor isn't too difficult, nor terribly expensive in the grand scheme of all the mods we do, so I'm going to try it and see if the problem goes away as an experiment.

[Efthreeoh]

Originally Posted by ashmostro

Right, but that's not the "undocumented feature" that applies here.

Capacitors can fail. Terminations can fail. Am I sure that's what is happening here? No... But it feels more like an electro-mechanical issue to me by its correlation to temperature.

Actually I suspect moisture in the oil is to blame (affects the dielectric constant), which is why reports of this issue are so common in the winter and almost non events in warmer climates. But that's just one of my theories. Replacing the sensor isn't too difficult, nor terribly expensive in the grand scheme of all the mods we do, so I'm going to try it and see if the problem goes away as an experiment.

I've been through all of this with the shop manager at BMW of Sterling. The shop manager is a former BMW tech and factory trained; he knows his shit. I asked every question I could think of regarding oil sensor. When the sensor fails it throws trouble codes (BMW codes), so I'd suggest you scan your car with a BMW scan tool before wasting time and money on a $160 oil sensor. Just my advice.

[ashmostro]

Good to know - I will

[DR-JEKL]

I installed a M3 gauge cluster to my 335i, everything worked except i got a cruise control malfunction error then a few weeks later i noticed when i went to check the oil level, the check would time out and revert back to the normal screen without providing a reading.

Eventually I wacked back in the 335i cluster so i could use my cruise control and no more cruise control malfunction error on startup yet the cruise wont work and now the 335i cluster wont perform the oil level check either!

Anyone got any ideas??

[1seriesfan]

Smoke rolling out of my ears today with this issue also. Took my '06 E90 in for defective oil level sensor replacement last winter, to the tune of almost $500, oil change included.

All was good until several months later now (in cold weather) when the low level warning indicator came on again. The last few days however, there was no warning indicated (warmer weather) and it shows normal, full of oil.

Took the car back to the dealer today to let them scan it anyway as they said the sensor would be covered under the parts warranty. When I got there, they said they feel the sensor isn't bad, but instead a software update is needed for an additional $150! Needless to say, I told the SA where they could stick it, and I stood my ground! And no, I'm not too worried about the car running out of oil, I always keep an eye out for leaks, etc. I also change my oil frequently and will take my chances.

Not blaming the dealer entirely, they said the TSB advises a reprogramming be done to "calibrate" the sensor. In my opinion, why doesn't BMW cover this as part of the original repair? The software update should be part of the procedure/labor cost when I took it there originally! After all, it's simply a matter of hooking up one cable and waiting.

Microsoft and other software companies update with Service Packs for free when you buy or use their products, why does BMW feel they're so special?! I could see the point if I was running there every month just to get the "latest and greatest," but originally there was a broken part problem here! I also don't want to be "nickeled and dimed!"

I also asked, "with the full software update (other than calibrating the sensor 10 months later) what does my $150 buy me?" The SA (nice guy, not blaming him) couldn't answer. Does anyone know? If I'm going to get much better fuel mileage or something (which might justify the expense a little) at least I'd maybe feel better about it.

Am I out of line, guys? I want a dipstick back, that never cost me a penny!

[Brian_TII]

Originally Posted by 1seriesfan

Smoke rolling out of my ears today with this issue also. Took my '06 E90 in for defective oil level sensor replacement last winter, to the tune of almost $500, oil change included.

All was good until several months later now (in cold weather) when the warning indicator came on again. The last few days however, there was no warning indicated (warmer weather) and it shows normal, full of oil.

Took the car back to the dealer today to let them scan it anyway as they said the sensor would be covered under the parts warranty. When I got there, they said they feel the sensor isn't bad, but instead a software update is needed for an additional $150! Needless to say, I told the SA where they could stick it, and I stood my ground! And no, I'm not too worried about the car running out of oil, I always keep an eye out for leaks, etc. I also change my oil frequently and will take my chances.

Not blaming the dealer entirely, they said the TSB advises a reprogramming be done to "calibrate" the sensor. In my opinion, why doesn't BMW cover this as part of the original repair? The software update should be part of the procedure/labor cost when I took it there originally! After all, it's simply a matter of hooking up one cable and waiting.

Microsoft and other software companies update with Service Packs for free when you buy or use their products, why does BMW feel they're so special?! I could see the point if I was running there every month just to get the "latest and greatest," but originally there was a broken part problem here! I also don't want to be "nickeled and dimed!"

I also asked, "with the full software update (other than calibrating the sensor 10 months later) what does my $150 buy me?" The SA (nice guy, I'm not blaming him) couldn't answer. Does anyone know? If I'm going to get much better fuel mileage or something (which might justify the expense a little) at least I'd maybe feel better about it.

Am I out of line, guys? I want a dipstick back, that never cost me a penny!

I agree with you. The dealer should just update it for you, I'd ask to speak to a manger over the service dept or even a sales manager. Make your case and be firm and persistent. They really should have updated it when you had it replaced 10 months ago if they really feel that's potentially an issue.

[Efthreeoh]

Originally Posted by 1seriesfan

Smoke rolling out of my ears today with this issue also. Took my '06 E90 in for defective oil level sensor replacement last winter, to the tune of almost $500, oil change included.

All was good until several months later now (in cold weather) when the low level warning indicator came on again. The last few days however, there was no warning indicated (warmer weather) and it shows normal, full of oil.

Took the car back to the dealer today to let them scan it anyway as they said the sensor would be covered under the parts warranty. When I got there, they said they feel the sensor isn't bad, but instead a software update is needed for an additional $150! Needless to say, I told the SA where they could stick it, and I stood my ground! And no, I'm not too worried about the car running out of oil, I always keep an eye out for leaks, etc. I also change my oil frequently and will take my chances.

Not blaming the dealer entirely, they said the TSB advises a reprogramming be done to "calibrate" the sensor. In my opinion, why doesn't BMW cover this as part of the original repair? The software update should be part of the procedure/labor cost when I took it there originally! After all, it's simply a matter of hooking up one cable and waiting.

Microsoft and other software companies update with Service Packs for free when you buy or use their products, why does BMW feel they're so special?! I could see the point if I was running there every month just to get the "latest and greatest," but originally there was a broken part problem here! I also don't want to be "nickeled and dimed!"

I also asked, "with the full software update (other than calibrating the sensor 10 months later) what does my $150 buy me?" The SA (nice guy, not blaming him) couldn't answer. Does anyone know? If I'm going to get much better fuel mileage or something (which might justify the expense a little) at least I'd maybe feel better about it.

Am I out of line, guys? I want a dipstick back, that never cost me a penny!

How many miles are on the car?

[1seriesfan]

Just over 80K.

[Blitz513]

Hello! New to the forum. I don't see an existing thread or post addressing this particular issue, but this seems to be a good place to start. I recently replaced the OZS sensor in my 2009 BMW 535xi. The car was randomly throwing elevated engine temperature, hot engine, and overheated engine warnings, putting the car into limp mode, and then usually resolving within a few seconds (but not always). On the computer, it looked like the oil temp was spiking during these episodes, but as at least one warning occurred when the vehicle was cold, it seemed to be a sensor problem. Indeed, changing the OZS sensor resolved the issue.

This was recently replaced, about two weeks ago. Since then, even though the oil was changed and service interval was reset about two weeks before the OZS sensor was changed, the service monitor has displayed the following message: "Observe recalculated oil change interval" and at the time of the sensor change, displayed 260 mi remaining on the oil life. That made its way to zero and is now negative, indicated ovedue service. I thought I could reset the service monitor per usual, but when I do so, the system ignores the reset attempt and continues to display all of this. Additionally, I do not think the level sensor is actually functioning as it was halfway between min and max when the sensor was installed; I added 1/2 quart and the level did not increase; shortly thereafter, it changed to min (one amber square) but is not adivsing me to add oil, only to have the system serviced.

There are no codes to clear, and there is no way to reset this using a computer and scan tool. Is there a process to initializing or calibrating a new OZS sensor?

Thank you!

Chris